Economic - several writers have noted the role of monastics as entrepreneurs.
Social - any good text about medieval monasticism can give you plenty of specific examples of this.
Missionary - some orders were more active in this regard than others.
Cultural - this is perhaps the best known of the work of medieval religious orders and included the creation of the great illuminated manuscripts of the age.
Unterseeboots or U-boats. Both are the German word for submarine.
No one branch or institution can become so powerful as to control the system completely because of the separation of powers. The separation of powers is important because it provides a vital system of ‘checks and balances
